1. What is the Simpson Diversity Index?

The Simpson Diversity Index (D) measures biodiversity by accounting for both species richness (number of species) and evenness (distribution of individuals among species). It ranges from 0 (no diversity) to nearly 1 (infinite diversity).

2. How Does the Calculator Work?

The calculator uses the Simpson Diversity Index equation:

Where:

• \( D \) — Simpson Diversity Index (0 to 1)
• \( n_i \) — Number of individuals of species i
• \( N \) — Total number of individuals

Explanation: The index represents the probability that two randomly selected individuals from the sample will belong to different species.

3. Interpretation of Results

Details: Higher values indicate greater diversity. Values closer to 0 suggest dominance by one or few species, while values closer to 1 indicate more even distribution across species.

4. Using the Calculator

Tips: Enter counts of individuals for each species, separated by commas. All counts must be positive integers. The calculator will sum all counts and compute the diversity index.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between Simpson and Shannon diversity indices?
A: Simpson's index is more sensitive to dominant species, while Shannon's index is more sensitive to rare species.

Q2: What is a good Simpson Diversity Index value?
A: Values above 0.5 are generally considered diverse, but interpretation depends on the ecosystem being studied.

Q3: Can I use this for non-biological diversity measurements?
A: Yes, the index can be adapted for any categorical diversity measurement (e.g., linguistic diversity, product diversity).

Q4: What are the limitations of this index?
A: It doesn't account for species identity or ecological importance, just abundance distribution.

Q5: How does sample size affect the index?
A: Very small samples may underestimate true diversity. Larger samples provide more reliable estimates.